package com_1;

public class Test4Demo {
    public static void main(String[] args) {

        useTest(new Test3() {
            @Override
            public int add(int x, int y) {
                return x-y;
            }
        });
    }
    public static void  useTest(Test3 t){
        int sum=t.add(10,20);
        System.out.println(sum);
    }
}
